This species is distinguished by the following set of characters: six branched pectoral-fin rays; interopercular odontodes 28-29; vertebrae 34-37; opercular odontodes 13; branchiostegal rays 9; absence of conspicuous papillae on ventral region of head; presence of pelvic girdle and fin; long rictal barbel, 40.0-73.0% of HL; pelvic fins not reaching the urogenital opening; caudal fin truncate to rounded; first pectoral-fin ray not prolonged as a filament; color pattern of the caudal fin, presenting blotches, spots, or a homogeneous dark-brown or gray pattern in the proximal region; presence of a narrow mid-lateral stripe in some specimens; head, 17.2-20.6% of SL; pelvic fins 10.3-16.0%, pectoral fins 7.5-9.8% of SL; color pattern of some specimens, consisting in a dark-gray to dark-brown, becoming lighter towards ventral portion of the body and head, and absence of chromatophores, or some specimens with irregular dark-brown blotches on the inner skin layer, larger than two or three times the diameter of the orbit, sometimes coalescing and forming larger blotches, and an interrupted stripe in the mid-lateral region of the flank, over a plain yellowish to brown background; branchiostegal rays 9 (Ref. 137457).